Electrical outlet box



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ELECTRICAL OUTLET BOX Filed Oct. 24, 1932 I INVENTOR. 24 FWQ1MBDAM 0'; 5 0/49 6 y ATTORN 5 Patented Mar. 10, 1936 UNITED STATES PATENT OFFICE signor to Frank Adam Mo., a. corporation of Missouri Electric Co}, St. Louis,

Application October '24, 1932, Serial No. 639,238

This invention relates to improvements in electrical outlet boxes such as are intended for use in floors, walls, or like places, adapted to house plug receptacles, or kindred connections, together with associated wiring. The subject matter of the present invention is contained in improvements over the electrical outlet box disclosed in a prior patent to Frederick B. Adam, No. 1,254,641, issued January 22, 1918.

An object of the present invention is to provide an adjustable, sectional, Water tight outlet box wherein each of the sections is provided with an expanded shoulder portion which provides for an improved gripping engagement between the sections and surrounding masonry, such as concrete in which the sections are embedded.

Another object of the invention is attained in the provision of a finishing ring provided with integral ears adapted to connect thering .to one of the box sections, thereby eliminating any need for bolts or rivets to hold the parts in assembled relation.

A further object is attained in the provision of a finishing ring having integral lug portions adapted to hold a plug respectacle, or electrical device or apparatus to be placed within the box.

A still further object of the present invention is to provide a resilient element between the box sections which will form a water tight universal joint to aid in making adjustments in the relative positions of the sections during the setting of the floor box and before a final set has occurred in the masonry such as a concrete floor.

A still further object of the present-invention is to provide, about a resilient member between the box sections, a metallic band which will effectively, electrically ground the sections.

Further objects and advantages will appear from the following descriptiomand from nae apjpended drawing, in which:

Fig. 1 is a sectional elevation of an assembled floor box, as taken along line l| in Fig.3;"Fig 2 is a plan view of the floor box in a concrete floor;

Fig. 3 is an elevation of the upper box section,

as viewed from the bottom thereof; Fig. 4 is a fragmentary sectional elevation, as taken along line 44 in Fig. 3; Fig. 5 is a fragmentary sectional elevation as taken along line 55 in Fig. 2, and Fig. 6 is a sectional elevation of the assembled fioor box shown with a protecting cover plate as employed when the box is not in use. Fig. 7 is a view of a portion of the packing used between the box sections.

Referring nowto the drawing'by numerals of reference, I0 represents, generally, a floor box assembly, composed, preferably, of a lower secti0n l2, of a circular box form, and an upper section IA of ring or tubular form, the sections being telescopically joined as best appears in Figs. 1 and 6. Both sections are preferably of sheet metal, press-formed to give the desired shape, the lower section thereof being provided with partly punched circular wall portions or knockouts l6 which may be easily removed, such as by 10 a hammer or other suitable instrument, to allow the end portion of conductor conduits (not shown) to be secured to the section. The rim l8 of the lower section is expanded to form an internal arcuate seat 26, for a purpose presently to ap- 15 pear, and an external shoulder portion 22 which is provided to maintain the section more firmly seated in the concrete floor 24. The latter feature of the lower section is particularly important in ,case the concrete, in drying, should shrink from its contact with the side walls of the section. In such instance, the expanded shoulder portion 22 would tendto keep the section in place, as the normal shrinkage of concrete is not sufficient to clear the shoulder.

As will be noted in Figs. 1 and 6, the section L4 is likewise provided with an extending shoulder portion 26, near its upper end 28, which serves a purpose similar to that of the shoulder 22, i. e., to maintain the section firmly seated in the top portion 30 of the concrete floor 24. The external diameter of the section [4, except for the shoulder 26, is ,less than the internal diameter of the bottom. section l2 so that it may slide partly within the section l2 in adjustable relation therewith. To facilitate the introduction of the upper to the lower section, the entering end of the upper section is inwardly tapered, orconstricted as shown. To produce a water tight connectionbetween the sections, and to aid in placing and frictionally positioning the upper section in proper angular and distance relation with the lower'section, a sealing ring or gasket 32, preferably of a resilient packing material, is secured in the arcuate seat portion 2:; of the lower section so as to engage the outer surface of the ring section M in a gripping or binding relation therewith. This method of connecting the telescoping sections insures a water tight coupling, and provides for adjustability in setting the sec- .5 tions as .the floor is poured, a feature which is of prime importance in obtaining a level set of the upper section to correspond to the surface of the finished floor, irrespective of the position of the lower section. It is, of course, understood that the normal position of the section I2 is with its outer edge parallel to the plane of the floor or wall. Due, however, to the frequency of misapplication, section i2 is shown as having a tilted set in the concrete portion 23.

In order to effectively electrically ground the sections, a metallic strip 3 3, preferably metal foil, may be spirally wound about the gasket member 32 so that portions of the strip contact with the outer surface of the member 53, and other portions thereof contact with the arcuate surface of the metal seat portion 28. The grounding of the sections may, of course, be effected by any suitable means, such as generally employed with floor boxes of the type herein disclosed.

The upper edge of the tubular section H1 is formed as an inwardly extending flange portion 36 upon which is seated a finishing ring member 38. A gasket ring ill, preferably of rubber, is placed between the ring 38 and the flange portion 36 to render the upper section assembly water tight. As will be noted in Figs. 3 and 4, the ring 38 is secured to the section M by lugs or ears 4! preferably formed integrally with the ring 38, bent to engage the under surface of the flange portion 36, in gripping relation therewith. As shown, there are three such lugs, each seated in a notch lla formed in the flange 33 to prevent the ring from turning, should it become loose. However, any desired number of lugs, or ears may be formed and employed in positioning the finishing ring on the flange seat 36. These assembly lugs further serve to ground the finishing ring through the upper and lower box sections.

Oppositely disposed, depending supporting lugs or members 42, preferably formed integrally with the finishing ring 38, are provided to support any desired unit of electrical apparatus usually placed in floor or Wall boxes of the present type. As illustrated in the present example, a cord plug receptacle 43 is seated upon a U shaped bracket member 44 having eared portions 45 which are secured to the supports 42, as by screws 46. The finishing ring 38, with its integral lugs and support members, is preferably stamped from a single blank of brass, or other suitable material as desired, to simplify its formation, an expedient which is of great manufacturing advantage, as will be readily understood.

A finishing plate 41, having a thickened central portion 48 and a threaded bore 49 therethrough, is seated within the finishing ring 38 with its upper surface flush with the upper edge of the ring 38. To furthher insulate the assembly from water seeping into the box, a gasket 50, which may be of a material and form similar to the gasket 40, is employed between the finishing ring and plate 41. The plate 4? is held in assembly by screws Fig. 5, which extend through the ring 38 and flange 33, although any other suitable means of securing the plate may be employed. One side of the plate 41 is substantially a plane surface, and the opposite side has the thickened central portion extending therefrom, as shown in Figs. 1 and 6. When the box is not in use, the plane surface side of the plate is placed uppermost, as in Fig. 6, and an externally threaded plug 52 secured in the threaded bore 49 to completely cover the floor box, and to result in an unbroken floor surface portion. When it is desired to place the floor box in use, the plate 41 is reversed to bring the thickened portion 48 uppermost, as in Fig. 1. A cord 53 and plug 54 may then be attached to the receptacle 43, and a bushing 55, of hard rubber, bakelite, or any other suitable insulating material, fitted into the threaded bore 49 of the plate 41. If desired, the bushing may be of the split type, as shown in Fig. 2, to enable the cord and plug to be removed, or exchanged for another, without having to remove the plug end from the cord to slip the bushing from its position about the cord. The halves of the bushing are conveniently provided with dowel connections, as appear in Fig. 2.

In assembling the floor box, the lower section I2 is set in the concrete 24, and to prevent any of the concrete mixture from getting into the section a cover (not shown) may be employed which fits the top portion of the section in binding engagement therewith. A cover (not shown) may also be employed in setting the upper section l4. Furthermore, if the lower section should happen to sink deep in its setting, as to make an adjustment with the upper section alone, impossible of attainment, an extension sleeve, or ring member (not shown) of suitable size and form, and preferably of the same material as the upper and lower sections, may be telescopically inserted between the sections so that the upper section may be brought to the level of the finished floor.

The particular features of the present improved floor box are the expanded shoulder portions 22 and 26 on the sections l2 and [4, respectively, the novel finishing ring 38, provided with integral assembly lugs, and integral support members for mounting any desired electrical apparatus within the box, and the metal foil strip 34, wound about the gasket 32, which effectively electrically connects the sections so that they may be properly grounded, as is generally required by safety rules. The ring 38 presents a particular manufacturing expedient, i. e., low material and stamping cost, and. rapid and easy assembly of the ring to the flange portion 36 of the upper section I l.

It is to .be understood that the present disclosure of this invention covers only a single embodiment thereof, and that substantial alterations and modifications may be made without departing from the spirit and full intended scope of the invention, as defined in the appended claims.

I claim as my invention:

1. In an electrical floor outlet device, a cylindrical closure shell having an external annular anchoring bead adjacent one end adapted to be imbedded in the material of the flo'or below the top surface thereof, the end portion beyond the bead being of reduced diameter and having a radially inturned flange to form a seat for a finishing ring also to be positioned below the top surface of the floor, whereby a substantial depth of floor material is supported by the reduced end portion of the shell to surround the seat for the finishing ring.

2. In an electrical floor outlet device, a cylindrical closure shell having an external annular anchoring bead adjacent one end adapted to be imbedded in the material of the floor below the top surface thereof, the end portion beyond the bead being of reduced diameter and having a radially inturned flange, and a finishing ring seated on said flange and having integral ears in clamping engagement with the inner edge of the flange for securing the ring upon the seat with its upper margin flush with the top surface of the floor.

3. In an electrical floor outlet device, a cylindrical closure shell having an external annular anchoring bead adjacent one end adapted to be imbedded in the material of the floor below the top surface thereof, the end portion beyond the bead being of reduced diameter and having a radially inturned flange, a finishing ring comprising an upstanding annular flange and a radially inturned flange seated on the inturned flange of the shell and secured thereto so that the upstanding flange is flush with the top surface of the floor, and a cover plate seated within the upstanding flange of the finishing ring to extend in a plane parallel with the top surface of the floor.

4. In an electrical floor outlet device, a cylindrical closure shell having an external annular anchoring bead adjacent one end adapted to be imbedded in the material of the floor below the top surface thereof, the end portion beyond the bead being of reduced diameter and having a radially inturned flange, a finishing ring comprising an upstanding annular flange and a radially inturned flange seated on the inturned flange of the shell so that the upstanding flange is flush with the top surface of the floor, the intumed flange of the finishing ring having fixture supporting means integral therewith extending into the shell.

5. In a device of the class described, a finishing ring for a floor outlet box adapted to be imbedded in the material of the floor below the top surface thereof, comprising an upstanding cylindrical cover receiving and retaining flange adapted to be secured to said box to extend flush with the top surface of the fioo'r, said cover retaining flange having a radially inturned flange integral therewith, said inturned flange having integral therewith a plurality of securing lugs and a plurality of angulate fixture supporting arms adapted to extend into the floor outlet box.

FREDERICK B. ADAM. 2Q 

